Refrigerating apparatus



E ff TCT ocr. 20,' 1942.

F. RA'rAl'czAK REFRIGERATING APPARATUS Filed Feb. 19, 1941 2 Sheets-Sheet 2 INV EN TOR. avc/.t I. $074/ eza A.

Patented Oct. 2K0, 1942` REFRIGERATING APPARATUS Francis I. Rataiczak, Dayton, Ohio, assgnor to General Motors Corporation, Dayton, Ohio, a

corporation of Delaware Application February 19, 1941, serial No. 379,646

y(Cl. (s2-.115)

10 Claims.

This invention relates to refrigerating apparatus and more particularly to the control of temiplertatures in a two-temperature refrigerator cabe There has been placed on the market a type of refrigerator commonly referred to as a Cold- Wall" refrigerator. This type refrigerator differs from conventional household refrigerators in that a partition is provided within the food storage chamber for dividing the interior of the chamber into upper and lower food storage spaces or compartments. In this type of refrigerator a secondary refrigerant circuit forming meanshas a portion thereof wrapped aroundthe walls of 'the lower compartment Vand has another portion thereof disposed in contact or in intimate heat exchange relationship with an evaporator or freezer coil, located in the upper compartment, of a lclosed primary refrigerating system. In this type of refrigerator there is an automatically actuated means for normally maintaining the evaporator of the primary refrigerating system and consequently the upper food compartment between -predetennined limits. The temperature of the lower compartment is dependent upon the temperature of the primary evaporator and is preferably maintained at a substantially constant higher temperature, or between predetermined higher temperature limits. There is also provided in this type refrigerator a manually actuated or adjustable means, commonly referred to as a cold-control, for modifying the. operation of the automatically actuated temperature control to vary the temperature of the primary evaporator from its normal predetermined limits in order to provide faster freezing of -substances placed in the evaporator to be frozen or for lowering the temperature of the upper compartment. Therefore, when the temperature of the primary evaporator is lowered or varied by the manually actuated means or cold-control, the temperature of the higher temperatured lower compartment is also reduced. For various reasons this reduction in the temperature of the higher temperatured lower compartment is not desirable and is detrimental to-certain foods stored therein. I contemplate the provision of means, in a refrigerator of the type described, for maintaining the temperature of the higher temperatured lower food storage compartment thereof at or between its preferred limits-at all times and particularly when the temperature of the upper compartment or when the temperature of the evaporator of the cold-control device.

f In carrying out these objects, it is a still fur- It is, therefore, an object of my invention to provide in a two-temperature refrigerating system. for a household refrigerator, incorporating a primary refrigerating system and a, secondary refrigerant circuit, a means for varying the temperature of the' primary evaporator which means also simultaneously controls the temperature produced by the secondary circuit.

It is another object of my invention to provideV ther andmore specific object of my invention to provide for the control of the temperature produced by a secondary refrigerant circuit, assol ciated with a primary refrigerating system which ing the door to the food chamber thereof in open position;

Fig. 2 is an enlarged vertical sectional view of the refrigerator cabinet disclosed in Fig. 1, showing a secondary refrigerating circuit associated with the evaporator of a primary refrigerating system mounted in the cabinet;

Fig. 3 is a fragmentary sectional view` of the refrigerator taken onv the line 3-3 of Fig.A 2, showing a temperature control for the secondary .refrigerant circuit in a normal position;

Fig. 4 is a view similar to Fig. 3, showing the temperature control for the secondary circuitA in an adjusted position; and Fig. 5 is a fragmentary diagrammatic view of a portion of the single control for both refrigerant circuits associated with the refrigerator cabinet.

Referring to the drawings, for illustrating my invention, I have shown in Fig. 1 thereof, a refrigerating apparatus ofthe household type iii-"vv cluding a refrigerator cabinetl I0, having. metal outerrwalls Il and an inner metal liner member l2. forx'ning a chamber therein. `Any suitable or mined low temperature limits.

associated therewith a means for `changing the setting of the mechanism therein desirable insulating material I4 (see Fig. 2) may be located between the vwalls II and liner l2. I'he front wall II of cabinet I0 has an aperture therein registering with an aperture provided in the front of liner I2 to provide an access opening leading to the interior of the insulated chamber. This accessopening is normally closed by an insulated door structure I5. The walls Ii depend below the insulated chamber and form a machine compartment I6 therebelow (see-Fig. 2), which compartment may house a refrigerant compressing and liquefying unit of a primary refrigerating system. A glass plate partition Il divides the insulated chamber into an upper food storage compartment I3 and a lower food storage compartment i3. The glass partition l'i is provided with a rubber or the like 4sealing gasket 2| at all four edges thereof and this gasket engages the three vertical walls of the liner I2 and the inner face of door I5. A primary evaporator or cooling element 23 is mounted in the upper food storage compartment I3 to cool the same and a secondary refrigerating circuit is associated with the cabinet I for cooling the lower food storage compartment I9. The evaporator 23 has a conduit connection 26 with the sealed motor-compressor 21 of a refrigerant compressing and liquefying unit located in the machine compartment I6, and another conduit connection 28 with.

a condenser 29 of the unit. Refrigerant evaporated within the cooling element or evaporator 23 of the primary refrigerating system' is withdrawn therefrom, through conduit 26, by the compressor 21 to cause the evaporator to produce a refrigerating effect. The evaporated or gaseous refrigerant withdrawn from the evaporator is compressed bythe compressor 2i and forwarded, by conduit 3i, to the condenser 23 where :lt is cooled and liquefied in any suitable or desirable manner. Liquid refrigerant ows from condenser 29 through conduit 23 into the lower portion of evaporator 23 under the control of a restrictor device 32 interposed in the conduit 2t. The motor and consequently the compressor, oi the sealed unit 21, is started and stopped automatically inresponse to the temperature of evaporator 23 by a snap-acting' switch represented by the reference character 33. Thus, I provide a thermostatic bulb 34 having a pipe connection 38 with an expansible and contractible bellows (not shown) located within the switch 33 for actuating same. Switch 33 controls an electric circuit leading from a power line to the motor-compressor unit 21 and including wires 31 connected to switch 33 and the wires 38 connected to unit 21 vas is conventional in the art. The thermostat 34 being responsive to the temperature of evaporator 23, actuates the switch 33 to start and stop operation of unit 21 for maintaining the primary evaporator and consequently the upper food storage compartment I8 between ,predeter- The automatically actuated switch 33 may beof the conventional or so called cold-control" type having manually to vary or lower the temperature of the evaporator 23, such, for example, as when faster freezing of a substance contained in a tray and placed in the evaporator is desired. For this purpose a rod extends through the housing of switch 33 and has a portion 4I thereof projecting forwardly of switch 33. A front cover plate 42 provided on evaporator 23 has an opening therein for the reception of a knob 43 which is securedto the end of rod portion 4i. This knob 43 has a pointer ,44 (see Fig. 5) thereon registering with a dial containing suitable numbers provided on the evaporator front plate 42. Rotation of knob 43 into registration with any one of the numbers on the dial indicates the amount of modification imparted to the mechanism ofV switch 33 to thereby alter its normal setting to cause modied operating periods of unit 21 for reducing the temperature produced by the evaporator .below its predetermined low limit. The rod has another portion d6 projecting rearwardly of the housing of switch 33 and extending through a bearing i member di (see Fig. 2), provided on the rear wall i2 oi evaporator 23. An arm 43 is rigidly secured to the end of the rod portion 46 for a purpose to be hereinafter more fully described. Switch 33 is normally set to maintain the evaporator 23 at temperatures below freezing in order that ice may be frozen at all times. The cooling of food compartment- I8 at such low temperature causes frost to form on the primary evaporator 23 .and also causes dehydration of the air and the maintenance of a low relative humidity within the compartment I3. It is desirable in the refrigerator disclosed to maintain the lower compartmentv I9, provided by the dividing partition l1, at a high temperature and high humidity and for this purpose I provide the refrigerator with a closed secondary volatile refrigerant circuit for cooling the compartment I3 as is conventional in such so-called Cold-Wa refrigerators. In order to cool the lower foodvstorage compartment i3. the outer surface of liner I2 has serpentine conduit loops 5i of a secondary refrigerant circuit intimately ysecured thereto.

The conduit loops 5i form an evaporator or a comprises a conduit loop 54 attached to a metal plate 55 (see Fig. 2) which is secured by screws in intimate thermal contact with a side wall of the primary evaporator 23. 'I'he goose-neck trap 53 prevents any liquid condensing inthe condensing loop portion 54 of the circuit from draining directly into the conduit 52 of the evaporatns portion oi! the circuit. The lowermost end 53 of the condensing portion of the secondary circuit is connected to a section of exible tubing 5l (see Fig. 3), which tubing is attached to the lower portion of an upstanding pipe section 5. A second section of flexible tubing 59 has its one end connected to the lower end of pipe 58 and hasits other end connected to a. downwardly extending conduitv portion 6I of the secondary circuit which forwards liquid refrigerant `from the condenser 54 to the evaporating loops 5I. The exible tubing 59 is provided with a loop portion to permit upward movement of pipe'58 relative to conduit 6I in a manner and for a purpose to'be presently described. A third section of flexible tubing 63 has its one end connected to' the top of trap 53 and has its other end connected to the upper portion of the pipe 58. Volatile refrigerant evaporating in the loops 5I cools the walls of compartment I9 and maintains the interior of this compartment at a temperature above freezing. The interior of compartment I9 is inherently maintained between temperature limits in accordance with the normal vueiied refrigerant ows conduit portions predetermined temperature limits of the primary evaporator 23 by association of the condenser of the secondary circuit therewith. The refrigerant after evaporating in loops 5I ofthe secondary circuit flows upwardly into the condensing loop 54 where it is condensed and liquefied by the low temperature of the primary evaporator. Liqfrom the lower portion 55 of the condenser 54 through the flexible tube 51, lower portion of pipe 58 and downwardly through the flexible tube 59 to the liquid forwarding conduit I.

It is desirable in this type of refrigerator to provide some means of maintaining the normal predetermined temperature limits within the lower food storage compartment I9 at all times irrespective of the lowering of the temperature of the primary evaporator 23 below its normal lo w temperature limit when faster freezing demands are placed thereupon. This will insure the maintenance of the high humidity within compartment I9 which is desirable for the variety of y condenser 54. Thus, the colder evaporator 29 is foods normally stored therein. Therefore, I provide a single means for varying the temperature of the primary evaporator 23 from its predetermined temperature limits and for also controlling the temperature of the secondary circuit when the temperature of the primary evaporator is so varied. This means ispreferably in the form of a movable or adjustable trap which varies the effectiveness of the condensing portion 54 of the secondary circuit by immersing same or a part thereof with volatile liquid contained in the secondary circuit. In the present disclosure, the flexibleftubing sections movement of pipe 58 relative to the stationary 52 and 5i of the secondary circuit. It will be understood that by raising the pipe 5B to elevate one end of the flexible tubing 51, liquid refrigerant will be trapped in the condenser 54. If the condensing portion 54 of the circuit has a. lesser volume than the volume of liquid refrigerant in the secondary circuit, then, if the tubing or conduit 51 is raised, the condensing portion 54 will gradually become filled with liquid refrigerant. When the condenser 54 is partially filled with liquid refrigerant its effectiveness is diminished and less refrigerant' will condense therein. When the condenser 54 becomes entirely filled with liquid refrigerant, it is f no longer effective to condense refrigerant therein. Consequently, the amount of refrigeration inthe evaporating portion 5I of the circuit and of the lower compartment I9 will decrease or cease in relation to the eectiveness of condenser 54. When the one end of tubing or conduit 51 is lowered then the refrigerant in the secondary circuit can circulate normally and refrigerate the lower compartment I9. 'I'he single means of the vpresent disclosure comprises a connection between the knob 43 of the cold-control" switch 51, 59 and 53 permit maintained the more the effectiveness of the condenser 54 of the secondary circuit is reduced in order to prevent the evaporator 5I of the secondary circuit from following the lowering temperature of the primary evaporator. When the knob 43 is returned to its normal or neutral No. l

position, after the desired period of low temperature of evaporator 23, theadjustable trap, comprisingtubes 51, 59 and pipe 59, no longerexists (see Fig. 3'), and the circulation of refrigerant in the secondary circuit occurs as usual in such systems. The amount of liquid refrigerant trapped in the condenser 54 from the remainder thereof in the secondary circuit depends upon the distance of upward movement of the pipe 58 and this movement depends upon the amount of rotation imparted to the knob 43 of switch tol anyone yof its positions intermediate the No. 1 and No. 7 positions. Thus. the effectiveness of the adjustable trap provided in the secondary circuit to immerse the condenser thereof with volatile liquid depends upon the position of or the amount of rotation of knob 43. The decrease in the effectiveness of the condenser 54 takes place gradually in accordance with movement of the knob progressively from its No. 1 position to its No. 4'1 position. In other words, the colder I the primary evaporator 23 is maintained, by the setting of knob 43, the more the liquid refrigerant will be trapped in the condenser of .the secondary circuit to control or minimize theamount of refrigeration producedby the evaporating portion thereby so that the temperature of the high humidity compartment I9 constant or between its normal predetermined limits. The purpose of the conduit portion extending from the juncture of the exible tubing 51 with tubing 59 to thetop of trap 53 and com2- prising pipe 59 and flexible tube r63 is to'break any siphoning action of a column of liquid refrigerant within the secondary circuit that might cause 39 and a portion of the secondary refrigerating circuit to trapliquid of the circuit in the condenser thereof. 'I'his means includes a link 55 having its ne end pivotally' secured, as at 51,` to

the` arm 49, mounted on rod portion 45 and 'havning its Iother end secured, as a't 59, to the closed .top endof pipe 58'. It will be noted that when the knob 43. of switch 43, is rotated in a counterclockwise direction (see Fig. 5) from its neutrai position No. 1, indicated on the dial provided on the 'evaporator-` front plate 42, yto the No. 7 position, the portions 4I' and 45 of the rod associated'I with the switch are also rotated. Rota-y tion of the rod portions 4I and 45 in addition to liquid refrigerant to be siphoned out of the adjustable trap while it is being elevated or after elevation of iiexible conduit section 51.

From the foregoing, it will be seen that. I have provided an improved refrigerator of th'.` household tyDe. wherein one compartment within the refrigerator'is cooled to a low temperature by a primary evaporator and another compartment therein is cooled to a higher temperature byv a secondary refrigerating circuit associated with the primary refrigerating system located in the refrigerator. By providing the single means for modifyingthe temperature of the primary evaporator vandfor controlling the temperature produced by the evaporator portion of the secondary circuit,-I insure the maintenance of a substantially constant'temperature and humidity within .the high'temperature food storage compartment' of the refrigerator. I have provided a remains substantially q ondary circuit including a portion in heat exchange relationship with said primary cooling means and another portion adapted to produce a refrigerating eiect, and a single means for varying the temperature of said primary cooling means from said predetermined temperature limits thereof and for maintaining the refrigerating effect produced by said anotherportion of said secondary circuit substantially constant when the 'temperature of said primary cooling means is so varied.

2, A refrigerating apparatus comprising, a primary cooling means normally maintained between predetermined temperature limits, a closed Ysecondary refrigerating circuit containing a volatile fluid and including a condensing portion in heat exchange relationship with said primary cooling means and an vaporating portion normally maintained between predetermined temperature limits', and a single means for causing the temperature of said primary cooling-means to be lowered below its normal predetermined low temperature limit and for maintaining the evaporating portion of said secondary circuit between its predetermined temperature limits when the temperature ci said primary cooling means is so lowered.

3. A rerigerating apparatus comprising, a

closed primary refrigerating system including an evaporator normally maintained' between 'predetermined temperature limits, a closed secondary circuit containing a volatile liquid, said secondary circuit including a condensing portion in heat exchange relationship with a part of said primary reirlgerating system and an evaporating portion normally maintained at a substantially constant temperature, and a single means for varying the temperature of the primary evaporator from said predetermined temperature limits thereof and for maintaining said, substantially constant temperature of the evaporating portion of said secondary circuit when the temperature oi said primary evaporator is so varied.

4. A reirigerating apparatus comprising, a

' closed primary refrigerating system including an evaporator normallymaintained between predetermined temperature'limits, a closed secondary circuit containing va volatile liquid, said secondary circuit including a condensing portion in heat exchange relationship with said primary evaporator and an evaporatin portion normally maintained at a substantially constant temperature, and a single means for varying the temperature of said primary evaporator from said predetermined temperature limits `thereof and for maintaining said substantially constant temperatureof the evaporating portion of said secondary l circuit when the temperatureof said primary evaporator is so varied, said means consisting of means for varying the eiectivenessof the condensing portion oi said secondary circuit by immersing at least a part thereof with the volatile liquid.

5. A refrigerating apparatus comprising, a closed primary refrigerating system including an evaporator normally maintained between predetermined temperature limits, a closed secondary Acircuit containing a volatile liquid, saidI secondary circuit including a condensing portion in heat exchange relationship with said primary evaporator and an evaporating portion normally maintained at a substantially constant temperature, and afsingle means for varying the temperature of said primary evaporator from said predetermined temperature limits thereof and i'or maintaining said substantially constant temperature of the evaporating portion of said secondary circuit when the temperature of said primary evaporator is so varied, said means consisting of means for elevating a part of said secondary circuit above at least a part of the condensing portion thereof to immerse said part of the condensing portion with the volatile liquid.

6. A refrigerating apparatus comprising in combination, a cabinet having a plurality of walls forming two food storage compartments therein,

a closed primary refrlgerating system associated with said cabinet and including an evaporator therein normally maintained Ybetween predetermined temperature limits for cooling one of said compartments, a secondary refrlgerating circuit associated with said cabinet and containying a volatile liquid, said secondary circuit including a condensing portion in heat exchangel e 7. A reirigerating apparatus comprising in' combination, a cabinet having a plurality of walls forming an upper food storage compartment and a lower food storage compartment therein, a closed primary refrigerating system associated with said cabinet and including an evaporator therein normally maintained between predetermined temperature limits ior cooling said upper compartment, a closed secondary refrlgerating circuit associated with said cabinet and containing a volatile liquid, said secondary circuit including a condensing portion in heat exchange relationship with said primary evaporator and an evaporating portion in heat exchange rela.- tionship with said lower compartment and nor-v mally maintained at a substantially constant temperature for cooling said lower compartment;` and a single means ior causing the temperature of said primary evaporator to be lowered below its normal predetermined lowtemperature limit and for maintaining said substantially constant' temperature of the evaporatlng portion ofv said secondary circuit when the temperature of said primary evaporator is so lowered..

8. A refrigerating apparatus comprising, a closed primary refrigerating system including an evaporator normally maintained between predetermined temperature limits, a closed secondary 2,299,653 kexchange relationship with a part of saidl prithe temperature of said prima-ry evaporator is so varied.

9.'In a revirigerating apparatus comprising a.v

closedprimary refrigerating system including an evaporator normally maintained between predetermined temperature limits and manually actuated means for causing the temperature of said evaporator to be lowered below its normal predetermined low temperature limit and also including a closed secondary iluid circulating system having a portion disposed in heat exchange relationship with a part of said primary refrigerating system for causing another portion thereof to produce a refrigerating effect, the method of maintaining the amount of refrigeration produced by said another portion of said secondary circulating system substantially constant when the temperature of said evaporator is lowered below its normal predetermined low temperature limit by said means which comprises, altering the ilow of iluid in said secondary circulating system simultaneously with and in response to movement of said manually actuated means.

10. A refrigerating apparatus comprising, a

closed. primary refrigerating system including an evaporator normally maintained between predetermined temperature limits, a closed secondary circuit containing a volatile refrigerant and including a condensing portion in heat exchange relationship with a part of said primary system and an evaporating portion, the construction and arrangement of said secondary circuit with re- .spect to said primary refrigerating system being such that said circuit has a normal predetermined effectiveness, and a single means for varying the temperature of the primary evaporator from its predeterminedtemperature limits and for simultaneously acting on said secondary circuit to change its effectiveness `for'controlling the temperature of `said evaporating portion thereof.

FRANCIS I. RATAICZAK. 

